One control arrangement for a single speed transmission having independently actuatable forward and reverse clutches has a control valve with a pair of directional spools for selectively actuating the clutches. Each of the directional spools are moved to a position for actuating the associated clutch by venting pressurized fluid from a chamber at one end of the associated spool through a solenoid valve. The solenoid valve is normally spring biased to the closed position to cause the chamber to become pressurized and is moved to the open or venting position upon energizing the coil thereof.
One of the problems encountered with such control arrangement is that if one of the clutches is partially engaged due to a leaky solenoid valve caused by contaminates, the partial engagement would cause slippage and serious damage to the clutch.
The present invention is directed to overcoming one or more of the problems as set forth above.